Bonded nonwoven fabrics and binders for the manufacture thereof



United States Patent Ofiice 3,284,233 Patented Nov. 8, 1966 3,284,233BONDED NDNWGVEN FABRlCfi AND BINDERS FOR THE MANUFACTURE THEREOF Fred H.Sexsmith, Passaic, Ni, assignor to Johnson &

Johnson, a corporation of New Jersey No Drawing. Filed Mar. 4, 1965,Ser. No. 437,257 15 Claims. (Cl. 11714tl) This application is acontinuation-in-part of my copendin-g application Serial No. 28,867,filed May 13, 1960, now abandoned.

The present invention relates to bonded nonwoven fabrics, to methods ofmaking such bonded nonwoven fabrics, and to binders for use in suchbonding methods. More particularly, the present invention relates tobonded nonwoven fabrics comprising cellulosic fibers and to binders ofcellulosic origin for use in bonding such cellulosic fibers.

Bonded nonwoven fabrics are generally produced by forming a base fibrouslayer or web of loosely assembled, overlapping and intersecting fibers,and depositing an adhesive bonding material thereon to bond the basefibrous web into an integral, self-sustaining nonwoven fabric. Suchfabrics exhibit various interdependent and inversely proportionatelevels of physical strength and softness and it has always been aprimary purpose of the industry to provide a nonwoven fabric whichcombines good physical strength and softness.

Among the adhesive bonding materials employed in the nonwoven fabricindustry are the water insoluble and alkali soluble binders of cellulosederivatives such as hydr-oxyethyl cellulose, carboxymethyl cellulose,and regenerated cellulose or viscose. The use of such cellulosederivative binder materials is particularly applicable for bondingnonwoven fabrics containing cellulosic fibers because of the chemicalaffinity between the cellulosic binder and the cellulosic fiber. Theyare also desirable because of their insensitivty to water in theregenerated state.

Polyolefins have many desirable properties known to the art and theseproperties could enhance the properties of an alkali soluble, waterinsoluble cellulose binder if a means of bringing the two together in abonding solution could be developed. This has not been possible in thepast because of the non-existence of one known solvent for both of theseconstituents.

This has been overcome by the instant invention which provides acolloidal dispersion of polyolefin particles in an alkaline solutionhaving dispersed therein a member selected from the group consisting ofhydroxyethyl cellulose, carboxymethyl cellulose and cellulose xantha-te,said dispersion being adapted to be app-lied to fibrous webs, to bindthe individualized fibers of said web, the bonded nonwoven fabric whichresults therefrom having increased softness, flexibility, drapeabilityand pliability, reduced stiffness, along with increased elongation tobreak.

The particular colloidal polyolefin which is selected to be incorporatedin the cellulose solution may be selected from a broad group of suchpolyolefin materials. Representative examples of such a group arepolyethylene, commonly identified by the chemical formula {-CH CH H-polypropylene, comm-only identified by the chemical for mula {CH CI-HCHH poly-l-butene, commonly identified by the chemical formula CH CH(C Hpoly-2- butene, commonly identified by the chemical formula {CH(CH)CH(CH and p olyisobutylene, commonly identified by the chemical formula-ECH O(CH It is to be noted that the polyolefinic materials used inapplying the principles of the present invention are actually saturatedchemical compounds and do not contain any canbon-to-carbon double bonds,even though they have been polymerized from monomeric materials such asethylene (high and low density), propylene, l-butene,

2-butene, isobutylene,.etc., which are unsaturated and containcarbon-t-o-canbon double bonds. Such saturation and absence ofcarbon-to-carbon double bonds in the polyolefinic materials createsexcellent stability and chemical inertness and avoids the main causes ofdiscoloration, and resinification on ageing. There is no necessity tostabilize these polyolefins against oxidation, such .as there is in thecase of rubber which requires a vulcanization treatment, and,consequently, the development of objectionable odors is avoided.Additionally, the polyolefins are nontoxic and innocuous. In this way,the use of the-polyolefins in the present invention renders thefinalproducts particularly attractive for surgical, medical and sanitarypurposes.

The polyolefins are available commercially in aqueous emulsion form andmay be used as such or, if available initially as a finely dividedpowder, may be dispersed in aqueous media with traces of a wetting agentto furnish stable emulsions of desired solids content.

The average particle size of the colloidal polyolefinic particles mustfall within a predetermined particle size range in order that thepurposes of the present invention be realized. It has been establishedthat particles having an average diameter of less than about microns aresuitable. More finely divided microdispersions, having an averageparticle diameter on the order of less than about 1 micron, have beenfound particularly useful where such finer size is more suitable for theparticular fabric being treated. The lower limit of the particle size ofthe polyolefinic particles will depend upon the particular purpose inmind. Within the more commercial aspects of the present invention, anaverage particle size of down to about 0.1 micron has been foundsatisfactory. One specific commercially available polyisobutylenecolloidal dispersion having an average particle size of about 0.5 micronand an average size distribution within the range of from about 0.05 toabout 1 micron has beenfound very satisfactory. Even finer particle sizeranges may be employed when desired or required, depending upon theparticular circumstances involved.

The term cellulose derivatives as used herein .is restricted to thosecellulose derivatives which. are soluble in alkaline solutions and mostsolvents for cellulose, yet insoluble in water and almost all of theother organic solvents. These cellulose derivatives include hydroxyethylcellulose, carboxymethyl cellulose and cellulose xanthate.

While cellulose itself is virtually insoluble in all solvents, thesolubility of its derivatives is dependent upon both the kind and degreeof substitution or addition effected with respect to the OH groupspresent in the cellulose monomer. This is true with respect tohydroxyethyl cellulose and canboxymethyl cellulose as is readilyappreciated by those skilled in the art of cellulose chemistry. Thus thesolubility of hydroxyethyl cellulose or canboxymethyl cellulose in an.alkaline solution is dependent upon the degree of substitution or theextent to which all three OH groups of the cellulose monomer, i.e.

are reacted. This is also true as to their insolubilityin Water.

Carboxymethyl cellulose is available commercially in the form of thesodium salt which is certainly applicable here.

Viscose as used herein is meant to define the cellulose xanthate or,more particularly, the sodium xanthate which is formed in the processwhere cellulose is treated with caustic soda and a soda cellulose isformed which is shredded, aged under controlled temperature and humidityto break down the original high chain polymer and treated with carbondisulfide followed by an aqueous solution of sodium hydroxide. Theresultant viscoussolution is known as viscose, or chemically as sodiumxanthate which is soluble in aqueous alkaline solutions. Sodium xanthatecan be dissolved in water but this is due to the presence of the sodiumwhich provides the alkaline medium. Regeneration of cellulose from thisviscous solution is well understood by the art.

The colloidal polyolefin dispersion may be incorporated into the alkalisolution containing the alkali soluble, water insoluble cellulosederivative by any desired means, such as a simple addition accompaniedby stirring. Complete compatibility has been established forsubstantially all proportions of the two, with no signs of polyolefincoagulation. The polyolefin particles are in the dispersed phase,whereas the cellulose derivative is dissolved in the continuous phase.There is no reaction between the cellulose derivative and thepolyolefin.

The colloidal polyolefin-cellulose derivative solution may be applied tothe fibrous web as an over-all impregnant, such as by dipping, sprayingor immersing processes, or it may be applied by intermittent binderprinting or other predetermined or random binder deposition techniques.If the solution is applied by printing techniques in the form ofdiscrete binder areas, such areas may be in the form of continuous ordiscontinuous straight or wavy lines, circles, annuli, rectangles,squares, diamonds, triangles, ellipses, ovals, or like rectilinear orcurvilinear figures or other similar regular or irregular figures.

Subsequent to the application of such solution to the fibrous web, thedissolved cellulose derivative is insolubilized or coagulated andregenerated to the water insoluble cellulose derivative form preferredas a binder material.

The final binder constitutes a composite of the additive properties ofthe alkali soluble cellulose derivative and the particular polyolefinused. Increasing the amount of the polyolefin in the binder of thisinvention will enhance the softness and flexibility contributed by thebinder to the final product. With a major proportion of polyolefin and avery minor amount of cellulose derivative, the latter would tend toenhance the film-forming propensity of the mixture and, because of itshigh efficiency, contribute to the strength without deleteriouslyaffecting the softness of the polyolefin.

The regenerated cellulose in the final product, or rather in the bindingcomposition of this invention on the nonwoven fabric as a binder,contributes its water insensitivity, the fact that it print bonds withvery little binder migration, the fact that the human body is notsensitive to cellulose, and the fact that it is an extremely efficientbinder for nonwovens, i.e. low solids add-on is required to developadequate strengths. The undesirable property of harshness which ischaracteristic of cellulose is modified by the polyolefin whichcontributes softness, but also its water insensitivity and its inertnessto the human body. In combination then, the better qualities of both areobtained, i.e. a softening of the viscose by the rubber, or, at theother extreme, an improvement in the rubber strength by the viscose. Inaddition, the addition of the polyolefin is a means of obtainingcontrolled restriction of fluid spread on the surface of a fabric bondedwith the composition of this invention.

Restricting fluid spread is of obviously great importance in sanitarynapkins and surgical bandages and sponges where the fluid should contactthe fabric, go through it and become absorbed by the absorbent mediaprovided, rather than spread along the surface of the fabric.

The amount of binder material (dry solids basis) to be applied to thefibrous starting layer or web may range from as little as about 1% toabout 100% or more by weight of the starting web (dry basis) andpreferably from about 10% to about by weight. The surface area of theweb covered by the binder will naturally be about 100% in the case ofthe over-all impregnated type. In the case of the intermittent patternvariety, the surface area of the web covered by the binder may bebetween about 7% to about of the total area of the web. However, ingeneral, it is preferred that the binder-containing areas cover at leastabout 12% and not more than about 30% of the total surface area of thefabric.

The proportions by weight (dry basis) of the cellulosic binder materialand the colloidal polyolefin in the bonded nonwoven fabric may be variedwithin relatively wide limits. From about 5 parts to about 95 parts byweight of the cellulosic binder material may be employed with from about95 parts to about 5 parts by weight of the polyolefin. Within the morecommercial aspects of the present invention, it has been foundpreferable to use from about 25 parts to about 75 parts by weight of thecellulosic binder material and from about 75 parts to about 25 parts byweight of the polyolefin. It is to be noted that these proportions arethose existing in the dry bonded nonwoven fabric and that care must beexercised in the initial blending or combining of the cellulose solutionand the colloidal polyolefin inasmuch as they are normally commerciallyavailable in solutions of widely varying solids content. For example, aviscose solution normally contains only between 6 and 7% by weight ofcellulose whereas a microdispersion of polyisobutylene, which maycontain up to or more by weight solids content.

The layer of overlapping and intersecting fibers, i.e. individualizedfibers, which is processed to form the bonded nonwoven fabric of thepresent invention may be formed by any one of a number of conventionaltechniques for depositing, arranging, or rearranging fibers in a web.These techniques include carding, garnetting, airlaying, papermakingmethods and the like. Individual webs or thin layers formed by one ormore of these techniques may be laminated to provide a thicker layer forconversion into a fabric. In general, the individual fibers extend in aplurality of diverse directions in general alignment with the majorplane of the fabric, overlapping, intersecting and supporting oneanother to form an open porous fibrous structure. The degree of fiberorientation in any particular direction will depend primarily. upon themethod of formation of the web. Webs formed by. airlaying techniquesnormally have very little orientation in any particular direction andare basically isotropic. On the other hand, webs formed by carding andgarnetting techniques are more or less predominantly oriented in thelong direction of the web. Each type of web has its own properties andcharacteristics and each is useful for particular purposes. Reference ismade to US. Patents 2,862,251; 2,705,687; 2,705,688; and 2,676,363 whichdisclose typical methods and apparatus for making such fibrous webs.

The fibrous web may contain natural or synthetic, vegetable, animal ormineral fibers such as cotton, silk, wool, vicuna, mohair, alpaca, flax,ramie, jute, etc.; synthetic or man-made fibers such as the cellulosicfibers, notably cuprammonium, viscose or regenerated cellulose fibers;cross-linked cellulosic fibers such as Corval and Topel; cellulose esterfibers such as cellulose acetate (Celanese) and cellulose tri-acetate(Arnel); the saponified cellulose ester fibers such as Fortisan andFortisan-36; the polyamide fibers such as nylon 420, nylon 6(polycaprolactam), nylon 66 (hexamethylene diamine-adipic acid), nylon610 (hexamethylene diaminesebacic acid), nylon 11 (ll-amino undecanoicacid Rilsan); protein fibers such as Vica-ra; halogenated hydrocarbonfibers such as Teflon ('polytetrafluoroethylene); hydrocarbon polyolefinfibers such as polyethylone and polypropylene; polyester fibers such asKodel and Dacron, vinyl fibers such as Vinyon and Saran;

tail by the following specificexamples.

acrylic fibers such as Orlon, Acrilan, Creslan, etc.; modacrylic fiberssuch as Dynel and Vcrel; mineral fibers such as glass, metal, etc.

The lengths of the individualized fibers in the starting fibrous web mayvary from about /8 inch or /2 inch up to about 2 /2 inches or more inlength, depending upon the particular properties and characteristicsrequired or desired in the resulting fibrous web. If desired, thefibrous layer may have added thereto, by a subsequent processing step,if necessary, from about 1 or 2% by weight up to about 100% by weight offibers other than those of textile length. In special cases, all of thetextile length fibers may be replaced by fibers other than of textilelength. These other fibers may be of papermaking length, which extendfrom about 78 inch in length down to about of an inch or less in length,which shorter fibers normally are not used in conventional methods ofproducing fibrous webs.

Illustrative of these short papermaking fibers are the naturalcellulosic fibers such as woodpulp and wood fibers, cotton linters,cotton hull shavings fibers, mineral fibers such as asbestos, glass,rock wool, et-c., or any of the herein-before-mentioned natural orsynthetic fibers in lengths less than about inch and down to about of aninch or less.

The denier of the individual synthetic fibers referred to above ispreferably in the range of the approximate thickness of the naturalfibers mentioned and consequently deniers in the range of from about 1to about 5 are preferred. Where greater opacity or greater coveringpower is desired, special fiber deniers of down to about A. or evenabout Mr may be employed. Where desired, deniers of up to about 8, 10,15, or higher may be used. The minimum and maximum denier are naturallydictated by the desires or requirements for producing a particularfibrous Web, by the machines and methods for producing the same, and soforth.

The weight of the fibrous web of starting material may 'be varied withinrelatively wide limits above a predetermined minimum value, dependingupon the requirements of the intermediate or the final products. Asingle, thin web of fibers, such as produced by a card, may have aweight of from about to about 250 or more grains per square yard and maybe used in the application of the principles of the present invention.Within the more commercial aspects of the present invention, however,web weights of from about 90 grains per square yard to about 800 grainsper square yard .are contemplated. If heavier web weights are desired,such as up to 2000 grains, for example, several of the individual websmay be combined into a laminated structure to obtain the desired weight.The product of one card may be folded,

doubled, tripled, etc., on itself to reach the heavier weight,

or a plurality of cards may be used and the individual .products stackedor laminated'for a similar purpose.

The invention will be further illustrated in greater de- It should beunderstood, however, that although these examples may features of theinvention, they are givenprimarily for purposes of illustration and theinvention in its broader aspects is not to be construed as limitedthereto.

Example I The starting fibrous material is a card web Weighing about 400grains per square yard and containing 1 /2 denier, 1%; inches staplelength viscose rayon fibers (regenerated cellulose). The improvement insoftness, flexibility and dimensional stability is determined asfollows: Test samples of the cardweb measuring approximately 18 incheslong (45.72 cms.) and. 8 inches wide (20.32 cms.) are selected and arelightly prebonded with polyvinyl alcohol binder.

The viscose (sodium cellulose xanthate) used to treat describe inparticular detail some of the more specific the card web test samples isa standard 7% caustic, 7% cellulose solution. The polyolefin added tothe viscose is polyisobutylene used as an elastomer emulsion, 55%solids, average particle size about 0.5 micron, particle sizedistribution from about 0.05 micron diameter (minimum) to about 1 microndiameter (maximum). The elastomer emulsion has a specific gravity ofabout 0.96, a weight per gallon of about 8.1 pounds, and a pH of 5-6.

Eight different binder formulations having varying proportions ofviscose and polyisobutylene are prepared as follows:

Polyiso- Polyiso- 'lotal Sample No. Viscose butylene butylene Binder(Grams) (Grams) (Percent (Percent Solids) Solids) 200 0 0 7. 0 175 25 4210. 7 150 50 G4 14. 4 125 75 7G 18. 1 100 84 21. 8 75 90 25. 4 50 94 29.O 25 97 32. 9

These viscose-polyisobutylene binder formulations all mixed well and aresmooth and creamy. They are applied substantially uniformly to theoriented card web test samples to about 300% wet pick-up by weight byhand mangling procedures. Standard acid coagulation andregenerationtechniques are used to coagulate and regenerate the viscose, followed byprolonged washing in water and subsequent air drying. The processingtakes place with the card web test samples in a relatively relaxedcondition. The physical evaluations of the resulting products are asfollows:

Final Tear Sample No. Dry Weight Gurley Final Strength (Grains/Stiffness Width (Long) Yard The Gurley Stifiness Tester is described onpage 43 in The Paper Trade Journal, December 20, 1934; its readings aswell as the tear strength readings are relative and show trends orimprovements over the control sample (No. 1) which does not containpolyisobutylene. improvement in softness and flexibility is shown by thesteady decrease in Gurley Stiffness readings as the percent ofpolyisobutylene in the binder formulation increases. The increase indimensional stability is noted in the decrease of shrinkage in width ofthe test samples as the percent of polyisobutylene in the binderformulation increases. Theincrease in dry tear strength is also to benoted. The reduced stiffness, the increased softness and flexibility,and the reduced shrinkage without any apparent serious loss of wetstrength, dry strength or color stability make the bonded nonwovenfabrics suitable for use as a wiping cloth.

Example II The starting fibrous material is a 600 grain per square yardcard web containing 100% bright viscose rayon fibers (regeneratedcellulose) having a denier of 1 /2 and a staple length of 1% inches.

Four different binder systems are used to bond the card webs: (1) 100%standard viscose solution containing 7% caustic, 7% cellulose, dilutedwith one part of 6% caustic solution for three parts of viscosesolution; (2) a viscose-polyisobutylene emulsion in which the polyiso-The The physical evaluations of the resulting products are as follows:

Final Dry Cross Percent Percent Weight Elongation Gurley SampleCellulose Polyethyl- (Grains/ Stiffness Solids one Solids Yard Dry WetThe reduced stiffness, the increased softness and drapeterms of materialtransfer and low wet migration. The fabricidentrficatrons andevaluations follow: ability and the increased cross elongation withoutany Final Percent Elongation Sample Binder Fabric Dry Weight Gurley(Grains/ Stiffness Yard Long Cross 640 22 7 28 664 is 0 49 696 6 10 59712 12 83 696 18 9 25 70s 11 9 28 723 5 12 25 672 11 70 712 9 10 74 688s 11 53 608 6 12 59 695' 6 14 91 640 5 9 36 696 5 11 37 582 4' 12 as 5764 12 44 The improvement in softness and flexibility is shown by therelatively constant decrease in Gurley Stiffness readings, as thepercent of polyisobutylene in the binder formulation increases. GurleyStiffness readings at low levels are not completely reliable orreproducible and are omitted from the above table. The increase in thepercent elongation to break in the long and cross direction is also tobe noted. The reduced stiffness, increased softness and flexibility andincreased elongation to break without any apparent serious loss of wetstrength, dry strength or stability color make the bonded nonwovenfabrics suitable for use as a hospital wash cloth.

As used herein, the term Masslinn nonwoven fabric (occasionallyidentified by the letter M) is intended to cover bonded nonwoven fabricssuch as disclosed in US. Patents 2,705,6862,705,688, issued April 5,1955. The term Keybak bundled fabric (occasionally identified by theletter K) is intended to cover nonwoven fabrics disclosed in US. Patents2,862,251, 3,081,514 and 3,081,515.

Example III The starting fibrous material is a 600 grain per square yardKeybak bundled fabric containing 100% viscose rayon fibers (regeneratedcellulose) having a denier of 1 /2 and a staple length of 1% inches.

Three different binder systems are used to bond the card webs: (l) 3parts of standard viscose solution containing 7% caustic, 7% cellulose,diluted with 1 part water but no added polyolefin; (2) 3 parts ofstandard viscose solution and 1 part of solids by weight polyethyleneaqueous dispersion; and (3) 2% parts of standard viscose solution and 1%parts of 40% solids by weight polyethylene aqueous dispersion. Thepolyethylene has a high molecular weight and is a very finely divided,dispersible powder having a particle size of 90 microns (diameter) orless.

The binders are applied to the card webs in an intermittent printpattern comprising wavy lines extending across the width of the cardweb, with four wavy lines to the inch as measured in the long direction.Standard coagulation and regeneration procedures are employed.

apparent serious loss of wet strength, dry strength, or color stabilitymake the bonded nonwoven fabric suitable for use as a disposable washcloth.

Although several specific examples of the inventive concept have beendescribed, the same should not be construed as limited thereby nor tothe specific features mentioned therein but to include various otherequivalent features as set forth in the claims appended hereto. It isunderstood that any suitable changes, modifications and variations maybe made without departing from the spirit and scope of the invention.

What is claimed is:

1. A colloidal dispersion of polyolefin particles in an alkalinesolution having dispersed therein a member selected from the group ofalkaline soluble cellulosic derivatives consisting of hydroxyethylcellulose, carboxymethyl cellulose and cellulose xanthate, saiddispersion being adapted to be applied to nonwoven fibrous webs to bindtogether the individualized fibers of said webs.

2. The dispersion of claim 1 wherein said polyolefin is polyethylene.

3. The dispersion of claim 1 wherein said polyolefin is polypropylene.

4. A colloidal dispersion of from about parts to about 5 parts by weightof polyolefin in the form of particles having an average diameter ofless than about microns, suspended in an alkaline solution havingdispersed therein from about 5 parts to about 95 parts, based on thetotal parts of the dispersion, of a member selected from the group ofalkaline soluble cellulosic derivatives consisting of hydroxyethylcellulose, carboxymethyl cellulose and cellulose xanthate, saiddispersion being adapted to be applied to a nonwoven fibrous web to bindtogether the individualized fibers of said web.

5. The dispersion of claim 4 wherein said polyolefin is polyethylene.

6. The dispersion of claim 4 wherein said polyolefin is polypropylene.

The Persion of claim 4 wherein said polyolefin is polyisobutylene,

8. The dispersion of claim 4 wherein said polyolefin is poly-l-butene.

9. A bonded nonwoven fabric of overlapping, intersecting individualizedfibers bonded together by binder areas constituting from about 7% toabout 100% of the total surface area of the fabric, said binder areascomprising a film of from about parts to about 95 parts by Weight of amember selected from the group of alkaline soluble cellulosicderivatives consisting of hydroxyethyl cellulose, carboxymethylcellulose and cellulose xanthate and from about 95 parts to about 5parts by Weight of polyolefin.

The fabric of claim 9 wherein the polyolefin is pol ethylene.

11. The fabric of claim 9 wherein the polyolefin is polypropylene.

12. The fabric of claim 9 wherein the polyolefin is polyisobutylene.

13. The fabric of claim 9 wherein the polyolefin is poly-l-butene.

14. A bonded nonwoven fabric of overlapping, intersecting individualizedfibers bonded together by binder areas constituting from about 7% toabout 35% of the total surface area of the fabric, said binder areascomprising a film of from about 5 parts to about 95 parts by Weight of amember selected from the group of alkaline soluble cellulosicderivatives consisting of hydroxyethyl cellulose, carboxymethylcellulose and cel lulose Xanthate and from about 95 parts to about 5parts by Weight of polyolefin.

15. The fabric of claim 14 wherein said binder areas comprise a film offrom about parts to about parts by weight of a member selected from thegroup of alkaline soluble cellulosic derivatives consisting ofhydroxyethyl cellulose, carboxymethyl cellulose and cellulose xanthateand from about 75 parts to about 25 parts by weight of a polyolefin.

References Cited by the Examiner UNITED STATES PATENTS 2,372,713 4/1945Curado et al 11714O 2,653,919 9/1953 Hunter 117161 2,868,742 1/1959Burnham 260-17 FOREIGN PATENTS 491,199 8/1938 Great Britain.

WILLIAM D. MARTIN, Primary Examiner.

S. W. ROTHSTEIN, Assistant Examiner.

9. A BONDED NONWOVEN FABRIC OF OVERLAPPING INTERSECTING INDIVIDUALIZEDFIBERS BONDED TOGETHER BY BINDER AREAS CONSTITUTING FROM ABOUT 7% TOABOUT 100% OF THE TOTAL SURFACE AREA OF THE FABRIC, SAID BINDER AREASCOMPRISING A FILM OF FROM ABOUT 5 PARTS TO ABOUT 95 PARTS BY WEIGHT OF AMEMBER SELECTED FROM THE GROUP OF ALKALINE SOLUBLE CELLULOSICDERIVATIVES CONSISTING OF HYDROXYETHYL CELLULOSE, CARBOXYMETHYLCELLULOSE AND CELLULOSE XANTHATE AND FROM ABOUT 95 PARTS TO ABOUT 5PARTS BY WEIGHT OF POLYOLEFIN.